Alternative mowing regimes to favour meadow biodiversity

In Switzerland, biodiversity promotion areas or BPAs (i.e. land under Swiss agri-environment schemes) account for around 15 % of the utilised agricultural area. While the main objective of BPAs is to promote farmland biodiversity, their effectiveness remains limited, in particular as regards the incidence of invertebrates in the lowlands. In this study, the mowing regime of lowland BPA hay meadows was manipulated to measure the impact on biodiversity. Results show that the abundance of invertebrates increases, – sometimes massively – when the first mowing date is delayed by one month (i.e. from mid-June to mid-July) and/or when a refuge is left uncut at each mowing event on 10 to 20 % of the meadow area. In addition, both of these alternative mowing regimes also increase the species richness of some invertebrate taxa. As regards vegetation, there was no sign of change after five years. These findings demonstrate both the short-term (i.e. over a season) and longterm (cumulative, i.e. from one year to the next) beneficial role of delaying mowing and leaving uncut refuges for the sake of biodiversity.

The risk of nitrate leaching is higher in field vegetable production than in arable crops or grassland. Different species of vegetables have different leaching potentials, which can be reduced through appropriate management.

In order to understand the diversity of insects colonizing oilseed rape, a survey focusing on beetles was conducted in a plot of winter rape in Agroscope Changins (Prangins VD). Beetles were captured with yellow water bowls over the whole cultivation period from August 2017 to June 2018. In total, 11,856 individuals were caught from exactly…

Recent studies show a decline in the abundance and diversity of wild pollinators, as well as an increase in honeybee mortality. These pollinators are an integral part of biodiversity and play an essential role in the growing of certain crops and in wild plant reproduction. In the Swiss cantons of Vaud and Jura, and in…